This invention is for a pressure reducing regulator that includes a pilot regulator mechanism.
U.S. Pat. No. 2,963,040 to Zimmer discloses a dome type regulator valve having an inlet fluidly connected to a main valve chamber with a main valve extending therein, the inlet also being connected by valve bores to a second valve chamber with there being a second valve for controlling flow thereto. A passage fluidly connects the second valve chamber to have fluid pressure act against a pressure plate and therethrough, against a diaphragm and a piston. When the piston moves downwardly, it opens the main valve to allow fluid flow to the outlet.
In U.S. Pat. No. 4,967,783 to Loos there is disclosed a recirculation valve with a pilot valve wherein there is a valve stem for controlling fluid flow from the inlet port to a recirculation (outlet) port. Inlet fluid flows to the interior of a sleeve having valve seats, a first valve stem being axially movable within the sleeve between open and closed positions relative to the valve seats. Fluid also flows from the inlet to a gap between the central shaft and a throat to a chamber that opens to the top closed end of the sleeve. A tubular pilot valve stem opens to the chamber, is slidably extended with the first valve stem and opens to a pilot valve chamber in the lower end of the first valve stem. The enlarged end of the pilot valve stem is abuttable against a valve seat to block fluid flow to the recirculation port. When fluid pressure in the piston chamber builds up, the first valve stem is moved to block fluid flow from the inlet to the recirculation port.
In order to make improvements in dome loaded pressure reducing regulators, this invention has been made.
The dome loaded pressure reducing regulator includes a regulator body that, together with a dome, form a control chamber having a piston therein. A main valve in a closed position blocks flow from the inlet to the top portion of the control chamber while, when the pressure in the top portion decreases relative to the pressure in the bottom portion, the piston moves to in turn move the main valve member to an open position to increase the pressure above the piston. A pilot valve in a closed position blocks fluid flow from the main valve bore to the pilot chamber while, when the pressure in the pilot chamber decreases, a diaphragm flexes to move the pilot valve member to permit fluid flow from the main valve bore to the pilot chamber regardless of the main valve member being in its open position or its closed position. The pilot chamber is in constant fluid communication with the outlet, including through bores in the main valve member and the piston to the control chamber below the piston and a bleed hole in the piston.
One of the objects of this invention is to provide a pressure reducing regulator having new and novel means for pilot regulation and dome loaded supply regulation in one regulator body. Another object of this invention is to provide a new and novel dome loaded portion in a pressure reducing regulator to minimize pressure decay due to flow increases. Still another object of this invention is to provide new and novel means in a dome pressure reducing regulator for venting pilot pressure downstream of the pressure flow through the main valve of the regulator. A different object of this invention is to provide new and novel means in a dome loaded supply reducing regulator to enable minimizing hysterises of static conditions for making pilot regulation a dynamic regulating valve.
Even though, for convenience terms, such as xe2x80x9cupperxe2x80x9d, xe2x80x9clowerxe2x80x9d, xe2x80x9ctopxe2x80x9d and xe2x80x9cbottomxe2x80x9d will be used in describing the pressure regulator, it is to be understood the usage of these terms is applicable to when the pressure regulator is in an upright position such as illustrated. However, it is to be further understood that the pressure regulator may be used in other than an upright position.